A seat cushion part of a vehicle seat has a pair of left and right side frames, and is structured such that a cushion frame in which plural beams are bridged across the pair of side frames is used, and a pad member of an urethane foam or the like is supported on the cushion frame. In order to give predetermined stiffness to the cushion frame to enhance its energy absorbing function, not only beams are bridged across front portions and rear portions of the pair of side frames, but also plural beams are bridged across them below buttocks around a lower side of a hip point (hip joint point of a human body model used for determining a design reference) where a large load in particular is liable to be applied, to thereby support an occupant's weight.